Merge branch 'master' of https://github.com/mathuo/dockview into master

module-build/tsconfig.esm.json

@@ -17,6 +17,7 @@
           "ES2016.Array.Include",
           "ES2017.String",
           "ES2018.Promise",
+          "ES2019",
           "DOM",
 		  ]
     }

module-build/tsconfig.json

@@ -17,6 +17,7 @@
           "ES2016.Array.Include",
           "ES2017.String",
           "ES2018.Promise",
+          "ES2019",
           "DOM",
 		  ]
     }

packages/dockview/src/__tests__/api/groupPanelApi.spec.ts

@@ -0,0 +1,78 @@
+import { IDockviewComponent, IGroupPanel } from '../..';
+import { DockviewPanelApiImpl, TitleEvent } from '../../api/groupPanelApi';
+import { GroupviewPanel } from '../../groupview/groupviewPanel';
+
+describe('groupPanelApi', () => {
+    test('title', () => {
+        const groupPanel: Partial<IGroupPanel> = {
+            id: 'test_id',
+            title: 'test_title',
+        };
+
+        const accessor: Partial<IDockviewComponent> = {};
+        const groupViewPanel = new GroupviewPanel(
+            <IDockviewComponent>accessor,
+            '',
+            {}
+        );
+
+        const cut = new DockviewPanelApiImpl(
+            <IGroupPanel>groupPanel,
+            <GroupviewPanel>groupViewPanel
+        );
+
+        let events: TitleEvent[] = [];
+
+        const disposable = cut.onDidTitleChange((event) => {
+            events.push(event);
+        });
+
+        expect(events.length).toBe(0);
+        expect(cut.title).toBe('test_title');
+
+        cut.setTitle('test_title_2');
+        expect(events.length).toBe(1);
+        expect(events[0]).toEqual({ title: 'test_title_2' });
+        expect(cut.title).toBe('test_title'); // title should remain unchanged
+
+        disposable.dispose();
+    });
+
+    test('onDidGroupChange', () => {
+        const groupPanel: Partial<IGroupPanel> = {
+            id: 'test_id',
+        };
+
+        const accessor: Partial<IDockviewComponent> = {};
+        const groupViewPanel = new GroupviewPanel(
+            <IDockviewComponent>accessor,
+            '',
+            {}
+        );
+
+        const cut = new DockviewPanelApiImpl(
+            <IGroupPanel>groupPanel,
+            <GroupviewPanel>groupViewPanel
+        );
+
+        let events = 0;
+
+        const disposable = cut.onDidGroupChange(() => {
+            events++;
+        });
+
+        expect(events).toBe(0);
+        expect(cut.group).toBe(groupViewPanel);
+
+        const groupViewPanel2 = new GroupviewPanel(
+            <IDockviewComponent>accessor,
+            '',
+            {}
+        );
+        cut.group = groupViewPanel2;
+        expect(events).toBe(1);
+        expect(cut.group).toBe(groupViewPanel2);
+
+        disposable.dispose();
+    });
+});

packages/dockview/src/__tests__/dockview/dockviewComponent.spec.ts

@@ -811,4 +811,31 @@ describe('dockviewComponent', () => {
 
         disposable.dispose();
     });
+
+    test('that removing a panel from a group reflects in the dockviewcomponent when searching for a panel', () => {
+        dockview.layout(500, 500);
+
+        const panel1 = dockview.addPanel({
+            id: 'panel1',
+            component: 'default',
+        });
+
+        const panel2 = dockview.addPanel({
+            id: 'panel2',
+            component: 'default',
+        });
+
+        expect(dockview.getGroupPanel('panel1')).toEqual(panel1);
+        expect(dockview.getGroupPanel('panel2')).toEqual(panel2);
+
+        panel1.group.model.removePanel(panel1);
+
+        expect(dockview.getGroupPanel('panel1')).toBeUndefined();
+        expect(dockview.getGroupPanel('panel2')).toEqual(panel2);
+
+        dockview.removePanel(panel2);
+
+        expect(dockview.getGroupPanel('panel1')).toBeUndefined();
+        expect(dockview.getGroupPanel('panel2')).toBeUndefined();
+    });
 });

packages/dockview/src/__tests__/groupview/groupview.spec.ts

@@ -444,4 +444,19 @@ describe('groupview', () => {
         groupview.model.closeAllPanels();
         expect(removeGroupMock).toBeCalledWith(groupview);
     });
+
+    test('that group is set on panel during onDidAddPanel event', () => {
+        const cut = new DockviewComponent(document.createElement('div'), {
+            components: {
+                component: TestContentPart,
+            },
+        });
+
+        const disposable = cut.onDidAddPanel((panel) => {
+            expect(panel.group).toBeTruthy();
+        });
+
+        const panel = cut.addPanel({ id: 'id', component: 'component' });
+        disposable.dispose();
+    });
 });

packages/dockview/src/dnd/droptarget.ts

@@ -11,6 +11,8 @@ export enum Position {
     Center = 'Center',
 }
 
+type Quadrant = 'top' | 'bottom' | 'left' | 'right';
+
 export interface DroptargetEvent {
     position: Position;
     nativeEvent: DragEvent;
@@ -100,60 +102,18 @@ export class Droptarget extends CompositeDisposable {
                     const xp = (100 * x) / width;
                     const yp = (100 * y) / height;
 
-                    let isRight = false;
+                    const quadrant = this.calculateQuadrant(
-                    let isLeft = false;
+                        this.options.validOverlays,
-                    let isTop = false;
+                        xp,
-                    let isBottom = false;
+                        yp
-
+                    );
-                    switch (this.options.validOverlays) {
-                        case 'all':
-                            isRight = xp > 80;
-                            isLeft = xp < 20;
-                            isTop = !isRight && !isLeft && yp < 20;
-                            isBottom = !isRight && !isLeft && yp > 80;
-                            break;
-                        case 'vertical':
-                            isTop = yp < 50;
-                            isBottom = yp >= 50;
-                            break;
-                        case 'horizontal':
-                            isLeft = xp < 50;
-                            isRight = xp >= 50;
-                            break;
-                    }
 
                     const isSmallX = width < 100;
                     const isSmallY = height < 100;
 
-                    toggleClass(this.overlay, 'right', !isSmallX && isRight);
+                    this.toggleClasses(quadrant, isSmallX, isSmallY);
-                    toggleClass(this.overlay, 'left', !isSmallX && isLeft);
-                    toggleClass(this.overlay, 'top', !isSmallY && isTop);
-                    toggleClass(this.overlay, 'bottom', !isSmallY && isBottom);
 
-                    toggleClass(
+                    this.setState(quadrant);
-                        this.overlay,
-                        'small-right',
-                        isSmallX && isRight
-                    );
-                    toggleClass(this.overlay, 'small-left', isSmallX && isLeft);
-                    toggleClass(this.overlay, 'small-top', isSmallY && isTop);
-                    toggleClass(
-                        this.overlay,
-                        'small-bottom',
-                        isSmallY && isBottom
-                    );
-
-                    if (isRight) {
-                        this._state = Position.Right;
-                    } else if (isLeft) {
-                        this._state = Position.Left;
-                    } else if (isTop) {
-                        this._state = Position.Top;
-                    } else if (isBottom) {
-                        this._state = Position.Bottom;
-                    } else {
-                        this._state = Position.Center;
-                    }
                 },
                 onDragLeave: (e) => {
                     this.removeDropTarget();
@@ -181,6 +141,87 @@ export class Droptarget extends CompositeDisposable {
         this.removeDropTarget();
     }
 
+    private toggleClasses(
+        quadrant: Quadrant | null,
+        isSmallX: boolean,
+        isSmallY: boolean
+    ) {
+        if (!this.overlay) {
+            return;
+        }
+
+        const isLeft = quadrant === 'left';
+        const isRight = quadrant === 'right';
+        const isTop = quadrant === 'top';
+        const isBottom = quadrant === 'bottom';
+
+        toggleClass(this.overlay, 'right', !isSmallX && isRight);
+        toggleClass(this.overlay, 'left', !isSmallX && isLeft);
+        toggleClass(this.overlay, 'top', !isSmallY && isTop);
+        toggleClass(this.overlay, 'bottom', !isSmallY && isBottom);
+
+        toggleClass(this.overlay, 'small-right', isSmallX && isRight);
+        toggleClass(this.overlay, 'small-left', isSmallX && isLeft);
+        toggleClass(this.overlay, 'small-top', isSmallY && isTop);
+        toggleClass(this.overlay, 'small-bottom', isSmallY && isBottom);
+    }
+
+    private setState(quadrant: Quadrant | null) {
+        switch (quadrant) {
+            case 'top':
+                this._state = Position.Top;
+                break;
+            case 'left':
+                this._state = Position.Left;
+                break;
+            case 'bottom':
+                this._state = Position.Bottom;
+                break;
+            case 'right':
+                this._state = Position.Right;
+                break;
+            default:
+                this._state = Position.Center;
+                break;
+        }
+    }
+
+    private calculateQuadrant(
+        overlayType: DropTargetDirections,
+        xp: number,
+        yp: number
+    ): Quadrant | null {
+        switch (overlayType) {
+            case 'all':
+                if (xp < 20) {
+                    return 'left';
+                }
+                if (xp > 80) {
+                    return 'right';
+                }
+                if (yp < 20) {
+                    return 'top';
+                }
+                if (yp > 80) {
+                    return 'bottom';
+                }
+                break;
+            case 'vertical':
+                if (yp < 50) {
+                    return 'top';
+                }
+                return 'bottom';
+
+            case 'horizontal':
+                if (xp < 50) {
+                    return 'left';
+                }
+                return 'right';
+        }
+
+        return null;
+    }
+
     private removeDropTarget() {
         if (this.target) {
             this._state = undefined;

packages/dockview/src/dockview/dockviewComponent.ts

@@ -7,7 +7,7 @@ import { Position } from '../dnd/droptarget';
 import { tail, sequenceEquals } from '../array';
 import { GroupviewPanelState, IGroupPanel } from '../groupview/groupPanel';
 import { DockviewGroupPanel } from './dockviewGroupPanel';
-import { CompositeDisposable, IValueDisposable } from '../lifecycle';
+import { CompositeDisposable } from '../lifecycle';
 import { Event, Emitter } from '../events';
 import { Watermark } from './components/watermark/watermark';
 import {
@@ -100,7 +100,6 @@ export interface IDockviewComponent extends IBaseGrid<GroupviewPanel> {
     getGroupPanel: (id: string) => IGroupPanel | undefined;
     fireMouseEvent(event: LayoutMouseEvent): void;
     createWatermarkComponent(): IWatermarkRenderer;
-
     // lifecycle
     addEmptyGroup(options?: AddGroupOptions): void;
     closeAllGroups(): void;
@@ -113,13 +112,17 @@ export interface IDockviewComponent extends IBaseGrid<GroupviewPanel> {
     focus(): void;
     toJSON(): SerializedDockview;
     fromJSON(data: SerializedDockview): void;
+    //
+    readonly onDidRemovePanel: Event<IGroupPanel>;
+    readonly onDidAddPanel: Event<IGroupPanel>;
+    readonly onDidActivePanelChange: Event<IGroupPanel | undefined>;
 }
 
 export class DockviewComponent
     extends BaseGrid<GroupviewPanel>
     implements IDockviewComponent
 {
-    private readonly _panels = new Map<string, IValueDisposable<IGroupPanel>>();
+    // private readonly _panels = new Map<string, IValueDisposable<IGroupPanel>>();
 
     // events
     private readonly _onTabInteractionEvent = new Emitter<LayoutMouseEvent>();
@@ -133,17 +136,30 @@ export class DockviewComponent
     private readonly _onDidDrop = new Emitter<DockviewDropEvent>();
     readonly onDidDrop: Event<DockviewDropEvent> = this._onDidDrop.event;
 
+    private readonly _onDidRemovePanel = new Emitter<IGroupPanel>();
+    readonly onDidRemovePanel: Event<IGroupPanel> =
+        this._onDidRemovePanel.event;
+
+    private readonly _onDidAddPanel = new Emitter<IGroupPanel>();
+    readonly onDidAddPanel: Event<IGroupPanel> = this._onDidAddPanel.event;
+
+    private readonly _onDidActivePanelChange = new Emitter<
+        IGroupPanel | undefined
+    >();
+    readonly onDidActivePanelChange: Event<IGroupPanel | undefined> =
+        this._onDidActivePanelChange.event;
+
     // everything else
     private _deserializer: IPanelDeserializer | undefined;
     private _api: DockviewApi;
     private _options: DockviewComponentOptions;
 
     get totalPanels(): number {
-        return this._panels.size;
+        return this.panels.length;
     }
 
     get panels(): IGroupPanel[] {
-        return Array.from(this._panels.values()).map((_) => _.value);
+        return this.groups.flatMap((group) => group.model.panels);
     }
 
     get deserializer(): IPanelDeserializer | undefined {
@@ -235,7 +251,7 @@ export class DockviewComponent
     }
 
     getGroupPanel(id: string): IGroupPanel | undefined {
-        return this._panels.get(id)?.value;
+        return this.panels.find((panel) => panel.id === id);
     }
 
     setActivePanel(panel: IGroupPanel): void {
@@ -296,35 +312,6 @@ export class DockviewComponent
         }
     }
 
-    private registerPanel(panel: IGroupPanel): void {
-        if (this._panels.has(panel.id)) {
-            throw new Error(`panel ${panel.id} already exists`);
-        }
-
-        this._panels.set(panel.id, {
-            value: panel,
-            disposable: {
-                dispose: () => {
-                    /** noop */
-                },
-            },
-        });
-    }
-
-    private unregisterPanel(panel: IGroupPanel): void {
-        if (!this._panels.has(panel.id)) {
-            throw new Error(`panel ${panel.id} doesn't exist`);
-        }
-        const item = this._panels.get(panel.id);
-
-        if (item) {
-            item.disposable.dispose();
-            item.value.dispose();
-        }
-
-        this._panels.delete(panel.id);
-    }
-
     /**
      * Serialize the current state of the layout
      *
@@ -333,13 +320,10 @@ export class DockviewComponent
     toJSON(): SerializedDockview {
         const data = this.gridview.serialize();
 
-        const panels = Array.from(this._panels.values()).reduce(
+        const panels = this.panels.reduce((collection, panel) => {
-            (collection, panel) => {
+            collection[panel.id] = panel.toJSON();
-                collection[panel.value.id] = panel.value.toJSON();
             return collection;
-            },
+        }, {} as { [key: string]: GroupviewPanelState });
-            {} as { [key: string]: GroupviewPanelState }
-        );
 
         return {
             grid: data,
@@ -351,11 +335,9 @@ export class DockviewComponent
 
     fromJSON(data: SerializedDockview): void {
         this.gridview.clear();
-        this._panels.forEach((panel) => {
+        this.panels.forEach((panel) => {
-            panel.disposable.dispose();
+            panel.dispose();
-            panel.value.dispose();
         });
-        this._panels.clear();
         this._groups.clear();
 
         if (!this.deserializer) {
@@ -376,9 +358,7 @@ export class DockviewComponent
             new DefaultDeserializer(this, {
                 createPanel: (id) => {
                     const panelData = panels[id];
-                    const panel = this.deserializer!.fromJSON(panelData);
+                    return this.deserializer!.fromJSON(panelData);
-                    this.registerPanel(panel);
-                    return panel;
                 },
             })
         );
@@ -457,7 +437,6 @@ export class DockviewComponent
     }
 
     removePanel(panel: IGroupPanel): void {
-        this.unregisterPanel(panel);
         const group = panel.group;
 
         if (!group) {
@@ -491,9 +470,9 @@ export class DockviewComponent
         const group = this.createGroup();
 
         if (options) {
-            const referencePanel = this._panels.get(
+            const referencePanel = this.panels.find(
-                options.referencePanel
+                (panel) => panel.id === options.referencePanel
-            )?.value;
+            );
 
             if (!referencePanel) {
                 throw new Error(
@@ -551,7 +530,7 @@ export class DockviewComponent
         if (!target || target === Position.Center) {
             const groupItem: IGroupPanel | undefined =
                 sourceGroup?.model.removePanel(itemId) ||
-                this._panels.get(itemId)?.value;
+                this.panels.find((panel) => panel.id === itemId);
 
             if (!groupItem) {
                 throw new Error(`No panel with id ${itemId}`);
@@ -603,7 +582,7 @@ export class DockviewComponent
             } else {
                 const groupItem: IGroupPanel | undefined =
                     sourceGroup?.model.removePanel(itemId) ||
-                    this._panels.get(itemId)?.value;
+                    this.panels.find((panel) => panel.id === itemId);
 
                 if (!groupItem) {
                     throw new Error(`No panel with id ${itemId}`);
@@ -632,6 +611,9 @@ export class DockviewComponent
                 kind: GroupChangeKind.PANEL_ACTIVE,
                 panel: this._activeGroup?.model.activePanel,
             });
+            this._onDidActivePanelChange.fire(
+                this._activeGroup?.model.activePanel
+            );
         }
     }
 
@@ -677,24 +659,25 @@ export class DockviewComponent
                                 kind: GroupChangeKind.ADD_PANEL,
                                 panel: event.panel,
                             });
-                            break;
+                            if (event.panel) {
-                        case GroupChangeKind2.GROUP_ACTIVE:
+                                this._onDidAddPanel.fire(event.panel);
-                            this._onGridEvent.fire({
+                            }
-                                kind: GroupChangeKind.GROUP_ACTIVE,
-                                panel: event.panel,
-                            });
                             break;
                         case GroupChangeKind2.REMOVE_PANEL:
                             this._onGridEvent.fire({
                                 kind: GroupChangeKind.REMOVE_PANEL,
                                 panel: event.panel,
                             });
+                            if (event.panel) {
+                                this._onDidRemovePanel.fire(event.panel);
+                            }
                             break;
                         case GroupChangeKind2.PANEL_ACTIVE:
                             this._onGridEvent.fire({
                                 kind: GroupChangeKind.PANEL_ACTIVE,
                                 panel: event.panel,
                             });
+                            this._onDidActivePanelChange.fire(event.panel);
                             break;
                     }
                 })
@@ -732,7 +715,6 @@ export class DockviewComponent
             params: options?.params || {},
         });
 
-        this.registerPanel(panel);
         return panel;
     }
 
@@ -778,4 +760,12 @@ export class DockviewComponent
             group.value.model.containsPanel(panel)
         )?.value;
     }
+
+    public dispose(): void {
+        super.dispose();
+
+        this._onDidActivePanelChange.dispose();
+        this._onDidAddPanel.dispose();
+        this._onDidRemovePanel.dispose();
+    }
 }

packages/dockview/src/dockview/dockviewGroupPanel.ts

@@ -1,4 +1,3 @@
-import { GroupChangeKind2 } from '../groupview/groupview';
 import { DockviewApi } from '../api/component.api';
 import { DockviewPanelApiImpl } from '../api/groupPanelApi';
 import {
@@ -147,20 +146,6 @@ export class DockviewGroupPanel
         this._group = group;
         this.api.group = group;
 
-        this.mutableDisposable.value = this._group.model.onDidGroupChange(
-            (ev) => {
-                if (ev.kind === GroupChangeKind2.GROUP_ACTIVE) {
-                    const isVisible = !!this._group?.model.isPanelActive(this);
-                    this.api._onDidActiveChange.fire({
-                        isActive: isGroupActive && isVisible,
-                    });
-                    this.api._onDidVisibilityChange.fire({
-                        isVisible,
-                    });
-                }
-            }
-        );
-
         const isPanelVisible = this._group.model.isPanelActive(this);
 
         this.api._onDidActiveChange.fire({

packages/dockview/src/gridview/baseComponentGridview.ts

@@ -74,6 +74,9 @@ export interface IBaseGrid<T extends IGridPanelView> {
     readonly groups: T[];
     readonly onGridEvent: Event<GroupChangeEvent>;
     readonly onDidLayoutChange: Event<void>;
+    readonly onDidRemoveGroup: Event<T>;
+    readonly onDidAddGroup: Event<T>;
+    readonly onDidActiveGroupChange: Event<T | undefined>;
     getPanel(id: string): T | undefined;
     toJSON(): object;
     fromJSON(data: any): void;
@@ -99,6 +102,16 @@ export abstract class BaseGrid<T extends IGridPanelView>
     private _onDidLayoutChange = new Emitter<void>();
     readonly onDidLayoutChange = this._onDidLayoutChange.event;
 
+    private readonly _onDidRemoveGroup = new Emitter<T>();
+    readonly onDidRemoveGroup: Event<T> = this._onDidRemoveGroup.event;
+
+    private readonly _onDidAddGroup = new Emitter<T>();
+    readonly onDidAddGroup: Event<T> = this._onDidAddGroup.event;
+
+    private readonly _onDidActiveGroupChange = new Emitter<T | undefined>();
+    readonly onDidActiveGroupChange: Event<T | undefined> =
+        this._onDidActiveGroupChange.event;
+
     get id() {
         return this._id;
     }
@@ -154,8 +167,7 @@ export abstract class BaseGrid<T extends IGridPanelView>
 
         this.element.appendChild(this.gridview.element);
 
-        // TODO for some reason this is required before anything will layout correctly
+        this.layout(0, 0, true); // set some elements height/widths
-        this.layout(0, 0, true);
 
         this.addDisposables(
             this.gridview.onDidChange(() => {
@@ -209,6 +221,7 @@ export abstract class BaseGrid<T extends IGridPanelView>
         this.gridview.addView(group, size ?? Sizing.Distribute, location);
 
         this._onGridEvent.fire({ kind: GroupChangeKind.ADD_GROUP });
+        this._onDidAddGroup.fire(group);
 
         this.doSetGroupActive(group);
     }
@@ -231,6 +244,7 @@ export abstract class BaseGrid<T extends IGridPanelView>
         }
 
         this._onGridEvent.fire({ kind: GroupChangeKind.REMOVE_GROUP });
+        this._onDidRemoveGroup.fire(group);
 
         if (!options?.skipActive && this._activeGroup === group) {
             const groups = Array.from(this._groups.values());
@@ -270,6 +284,7 @@ export abstract class BaseGrid<T extends IGridPanelView>
         this._onGridEvent.fire({
             kind: GroupChangeKind.GROUP_ACTIVE,
         });
+        this._onDidActiveGroupChange.fire(group);
     }
 
     public removeGroup(group: T) {
@@ -338,6 +353,11 @@ export abstract class BaseGrid<T extends IGridPanelView>
         super.dispose();
 
         this._onGridEvent.dispose();
+        this._onDidActiveGroupChange.dispose();
+        this._onDidAddGroup.dispose();
+        this._onDidRemoveGroup.dispose();
+        this._onDidLayoutChange.dispose();
+
         this.gridview.dispose();
     }
 }

packages/dockview/src/gridview/gridview.ts

@@ -17,6 +17,19 @@ import { Node } from './types';
 import { Emitter, Event } from '../events';
 import { IDisposable, MutableDisposable } from '../lifecycle';
 
+function findLeaf(candiateNode: Node, last: boolean): LeafNode {
+    if (candiateNode instanceof LeafNode) {
+        return candiateNode;
+    }
+    if (candiateNode instanceof BranchNode) {
+        return findLeaf(
+            candiateNode.children[last ? candiateNode.children.length - 1 : 0],
+            last
+        );
+    }
+    throw new Error('invalid node');
+}
+
 function flipNode<T extends Node>(
     node: T,
     size: number,
@@ -289,7 +302,8 @@ export class Gridview implements IDisposable {
 
     public deserialize(json: any, deserializer: IViewDeserializer) {
         const orientation = json.orientation;
-        const height = json.height;
+        const height =
+            orientation === Orientation.VERTICAL ? json.height : json.width;
         this._deserialize(
             json.root as ISerializedBranchNode,
             orientation,
@@ -308,7 +322,8 @@ export class Gridview implements IDisposable {
             root,
             orientation,
             deserializer,
-            orthogonalSize
+            orthogonalSize,
+            true
         ) as BranchNode;
     }
 
@@ -316,7 +331,8 @@ export class Gridview implements IDisposable {
         node: ISerializedNode,
         orientation: Orientation,
         deserializer: IViewDeserializer,
-        orthogonalSize: number
+        orthogonalSize: number,
+        isRoot = false
     ): Node {
         let result: Node;
         if (node.type === 'branch') {
@@ -333,12 +349,14 @@ export class Gridview implements IDisposable {
                 } as INodeDescriptor;
             });
 
+            // HORIZONTAL => height=orthogonalsize width=size
+            // VERTICAL => height=size width=orthogonalsize
             result = new BranchNode(
                 orientation,
                 this.proportionalLayout,
                 this.styles,
-                node.size,
+                isRoot ? orthogonalSize : node.size,
-                orthogonalSize,
+                isRoot ? node.size : orthogonalSize,
                 children
             );
         } else {
@@ -437,21 +455,6 @@ export class Gridview implements IDisposable {
             throw new Error('invalid location');
         }
 
-        const findLeaf = (candiateNode: Node, last: boolean): LeafNode => {
-            if (candiateNode instanceof LeafNode) {
-                return candiateNode;
-            }
-            if (candiateNode instanceof BranchNode) {
-                return findLeaf(
-                    candiateNode.children[
-                        last ? candiateNode.children.length - 1 : 0
-                    ],
-                    last
-                );
-            }
-            throw new Error('invalid node');
-        };
-
         for (let i = path.length - 1; i > -1; i--) {
             const n = path[i];
             const l = location[i] || 0;

packages/dockview/src/groupview/groupview.ts

@@ -19,7 +19,6 @@ export enum GroupChangeKind2 {
     ADD_PANEL = 'ADD_PANEL',
     REMOVE_PANEL = 'REMOVE_PANEL',
     PANEL_ACTIVE = 'PANEL_ACTIVE',
-    GROUP_ACTIVE = 'GROUP_ACTIVE',
 }
 
 export interface DndService {
@@ -365,6 +364,10 @@ export class Groupview extends CompositeDisposable implements IGroupview {
         ) {
             options.index = this.panels.length;
         }
+
+        // ensure the group is updated before we fire any events
+        panel.updateParentGroup(this.parent, true);
+
         if (this._activePanel === panel) {
             this.accessor.doSetGroupActive(this.parent);
             return;

packages/dockview/src/paneview/draggablePaneviewPanel.ts

@@ -5,7 +5,7 @@ import {
     PaneTransfer,
 } from '../dnd/dataTransfer';
 import { Droptarget, DroptargetEvent, Position } from '../dnd/droptarget';
-import { Emitter, Event } from '../events';
+import { Emitter } from '../events';
 import { IDisposable } from '../lifecycle';
 import { Orientation } from '../splitview/core/splitview';
 import {
@@ -14,23 +14,6 @@ import {
     PaneviewPanel,
 } from './paneviewPanel';
 
-interface ViewContainer {
-    readonly title: string;
-    readonly icon: string;
-}
-
-interface ViewContainerModel {
-    readonly title: string;
-    readonly icon: string;
-    readonly onDidAdd: Event<void>;
-    readonly onDidRemove: Event<void>;
-}
-
-interface IViewContainerService {
-    getViewContainerById(id: string): ViewContainer;
-    getViewContainerModel(container: ViewContainer): ViewContainerModel;
-}
-
 export interface PaneviewDropEvent2 extends DroptargetEvent {
     panel: IPaneviewPanel;
     getData: () => PaneTransfer | undefined;
@@ -101,6 +84,12 @@ export abstract class DraggablePaneviewPanel extends PaneviewPanel {
             this.handler,
             this.target,
             this.target.onDrop((event) => {
+                this.onDrop(event);
+            })
+        );
+    }
+
+    private onDrop(event: DroptargetEvent) {
         const data = getPaneData();
 
         if (!data) {
@@ -148,7 +137,5 @@ export abstract class DraggablePaneviewPanel extends PaneviewPanel {
         }
 
         containerApi.movePanel(fromIndex, toIndex);
-            })
-        );
     }
 }